The present invention relates broadly to registers or displays of accumulated data and, more particularly, to a machine readable display unit for displaying accumulated data in a machine readable format with particular applicability to electric rate meters or other consumption meters.
Electric utility rate meters, gas meters or other devices for displaying an on-going amount of energy consumption typically use alphanumeric indicia to display a number or other symbol, commensurate with energy consumed during a predetermined time period. The meter functions as a register and includes apparatus for changing the display responsive to energy use. The process is on-going and the number is constantly changing so long as energy is being consumed. In order for the utility company to determine energy usage per household, a person known generally as a "meter reader" is typically employed. This person travels the neighborhoods and visually inspects each meter, recording the displayed number. By subtracting a currently displayed number from the last recorded number, energy usage in the interim can be determined. Problems arise, however, if the meter reader transposes numbers or otherwise records an inaccurate reading from the meter display. This problem exists, not only for electric meters, but other rate meters, both gas and water, and on any instrumentation wherein displayed values are recorded by humans, such as instrumentation associated with power generation plants.
Machine readable codes have been around for several years. The most common machine readable code is a bar code. Widely implemented in the marketplace, bar codes are rapidly gaining increasing visibility in a broad range of diverse applications. A bar code symbol consists of a series of parallel, adjacent bars and spaces. Predetermined width patterns are used to represent actual data in the symbol. To read the information contained in a bar code symbol, a scanning device such as a light pen or other hand-held scanning device is moved across the symbol from one side to the other. As the scanning device is moved across the symbol, the width pattern of the bars and spaces is analyzed by the reading equipment and the original data is recovered. Some scanning devices do not require the operator to provide the scanning motion but include moving optical elements which allow the symbols, bars and spaces to be sequentially examined automatically. Currently, hand-held bar code scanners are available which can be communicated with a central computer to record and process data. Further, such hand-held scanners may include a transceiver which eliminates any wire connection between the scanning unit and a base station.
Bar codes are currently used in one aspect of rate meter reading. U.S. Pat. No. 5,278,551 to Wakatsuki et al discloses a system wherein a meter at each user's house has a user number displayed in bar code symbology thereon and a separate display section for displaying a reading. A data input terminal includes a bar code reader for reading the user number and a keyboard for manually inputting the present reading. With the Wakatsuki et al device, the meter reader must scan the identification code and then manually input the data reading from the meter display. Whether the meter reader is using paper and pen to record the data or a keyboard, the possibility of inaccurate readings remains.